1. Field of the Invention
This disclosure relates to an endoscopic video system with picture-in-picture capabilities and an endoscope for use in the endoscopic video system.
2. Description of the Related Art
Traditional endoscopic video systems generally include an endoscope having an objective lens system provided at a distal end of the endoscope that forms an image that can be seen on, for example, a video monitor. In medical applications, the endoscopic video systems are utilized to view images within a closed cavity of a patient. Often these endoscopic video systems can be used in conjunction with various sorts of endoscopic tools to perform a medical procedure. One such tool is a clip applier, which may utilize a clip to grasp and/or crimp/seal tissue by the single hand of an operating surgeon, and is described in commonly-assigned U.S. Patent Publication No. 2003/0040759, U.S. Patent Publication 2007/0049950 and U.S. Pat. No. 6,277,131, the entire contents of each document being expressly incorporated by reference herein. Typically, the endoscopic video system and the accompanying endoscopic tool are each inserted into the cavity usually through small incisions in the patient's skin. The endoscopic video system is generally equipped with a light source to illuminate the cavity and an image transmission unit to transfer images of the cavity captured by the objective lens system to the video monitor so that a user of the endoscopic video system can view the images.
The video monitor usually displays a 2D video image of the cavity of the patient. Because the endoscopic video system and the endoscopic tool are often inserted into the cavity at different incisions in the patient's skin, the 2D video image view angle aligns only with the endoscopic video system, and not with the endoscopic tool. A problem exists that it is difficult for a surgeon using the endoscopic video system and the endoscopic tool to accurately determine a position of the endoscopic tool relative to objects provided in the viewable cavity. For example, if the endoscopic tool were configured as a clip applier, and the surgeon were placing clips around an artery along the length of the artery at spaced intervals, the lack of visibility (at the site of the clip placement) hinders the ability of the surgeon to properly position a clip relative to a previously positioned clip. In fact, a surgeon viewing the video monitor to observe the movements of the clip applier in the cavity may accidentally place a clip too far from or too close to the previously positioned clip, or the surgeon may even accidentally cause the clip to overlap the previously positioned clip. Such accidental placement of the clip may damage the clip applier and the clips, and may even cause injury to the patient.